QGIS MCP Server

Start Editing

start_editing

Open an undoable edit session on a vector layer so that subsequent add, update, and delete operations go to the edit buffer until you commit or roll back the changes.

Instructions

Open an edit session on a vector layer. Subsequent add/update/delete calls go to the undoable edit buffer instead of the data source, until commit_edits or rollback_edits.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "layer_id": "<layer_id>"
    },
    "name": "start_editing"
  }
}

Input Schema

Name	Required	Description	Default
`layer_id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 13, 2026

TDQS

A4.2/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description carries the full burden. It reveals a key behavioral trait: edits are buffered rather than directly written until commit/rollback. This goes beyond a simple action statement, though it omits details like error handling or behavior if an edit session is already active.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single sentence that is information-dense and directly to the point. Every part earns its place, explaining the action, the buffer behavior, and the termination conditions without wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter command with no output schema, the description is largely complete: it states what the tool does, the effect on subsequent edits, and how to end the session. It lacks explicit mention of return values or preconditions, but these are not critical for this simple tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema provides only a string type for layer_id, and the description does not elaborate on the parameter. However, the phrase 'vector layer' and the self-explanatory name layer_id give sufficient context for a single-parameter tool, even though schema coverage is 0%.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Open') and resource ('edit session on a vector layer'), clearly distinguishing this from sibling tools like commit_edits and rollback_edits by explaining it starts a session that redirects edits to an undoable buffer.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly states that subsequent add/update/delete calls go to the edit buffer until commit_edits or rollback_edits, giving clear context for when to call this tool and the expected lifecycle. It does not explicitly list alternatives but the relationship to commit/rollback is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server